The invention relates to a roller screen intended for being mounted on the frame of a window opening, a door opening or the like, which roller screen comprises a gauze screen, a roll-up mechanism for said gauze screen, which is accommodated in a housing, a pull beam connected to the free end of said gauze screen, and guides for guiding said pull beam and the side edges of said gauze screen.
When a roller screen is to be mounted on a frame it is important that the guides take up a specific position with respect to the plane in which the gauze screen is moved to and fro. More in particular such guides generally include a slot, in which the pull beam and the side edges of the gauze screen are movable. Such a slot must be positioned to coincide with said plane.
Prior art guides have at least one flat outer side, which is placed in abutment with the frame in question upon being mounted. Thus the position (and in particular the spatial orientation) of the prior art guide is fixed, that is, said position is determined by the local shape of the frame in question. This may lead to mounting problems, however. For example, when the respective part of the frame does not extend fully horizontally or vertically, the spatial orientation imparted to the guide will be incorrect and its slot will not coincide with be inclined at an angle to said plane of the gauze screen. Moreover, mounting of the guide will be difficult when the frame includes a receding or projecting part. Usually it is necessary to revert to makeshift measures in the above cases, such as the use of fillers or fitting pieces, in order to fix the guide to the frame in a desired manner.
It is an object of the present invention to provide a solution for the above problems.
In order to accomplish that objective, the roller screen according to the invention is characterized in that said guides each consist of a substantially cylindrical outer housing, which can be fixed to the frame, and a likewise substantially cylindrical inner housing, which is accommodated in said outer housing in such manner as to be concentrically rotatable therein, which outer housing and which inner housing are each provided with a longitudinal slot which extends substantially along their entire length, wherein the longitudinal slots of the outer housing and that of the inner housing overlap, seen in their circumferential direction, in an operative position of the roller screen.
Regardless of the spatial orientation in which the outer housing is fixed due to the local shape of the frame, the inner housing, by rotating relative to the outer housing, is capable of taking up a position which ensures an optimum guidance of the pull beam and the side edges of the gauze screen in the overlapping longitudinal slots. When the guides are being mounted on the frame, the inner housing is on the one hand rotated relative to the outer housing and the outer housing is on the other hand moved relative to the frame prior to final fixation, all this in such a manner that the longitudinal slots of the outer housing and the inner housing lie substantially in the plane in which the gauze screen of the roller screen is moved to and fro. After such adjustment has taken place, the outer housing is fixed to the frame in any known manner (screws, bolts, glueing or the like).
The aspects as proposed make it possible to fix the guides to frames having different shapes in a quick and simple manner.
In one preferred embodiment of the roller screen according to the invention, the longitudinal slot of the outer housing is wider than the longitudinal slot of the inner housing, and the inner housing consists of a resilient material, at least adjacently to its longitudinal slot.
This enables the side edges of the gauze screen, which are generally provided with thickened guide cams, to move out of the guides when a large force is accidentally exerted on the gauze screen (for example when a person is unaware of the fact that a door opening is closed by the gauze screen and bumps into the gauze screen). Since the longitudinal slot of the outer housing is wider than the longitudinal slot of the inner housing, the resilient material of the inner housing is capable of bending outwards so as to provide room for the passage of the guide cams on the side edges of the gauze screen.
In this connection it is furthermore preferable that the longitudinal slot of the outer housing extends beyond the two sides of the longitudinal slot of the inner housing, seen in circumferential direction.
In principle it would suffice for the wider longitudinal slot of the outer housing to extend only beyond one side of the narrower longitudinal slot of the inner housing (in which case the slot edges of the two longitudinal slots will substantially coincide on one side). In that case only one longitudinal edge of the longitudinal slot could bend aside. In accordance with the present embodiment, however, it has been decided to form the longitudinal slot of the outer housing with a greater width on both sides of the narrower longitudinal slot (of the inner housing). This configuration enables the two longitudinal edges of the narrower longitudinal slot of the inner housing to move apart so as to release one edge of the gauze screen, if this should be necessary.
In accordance with another embodiment, in order to further enhance the mobility of the parts of the inner housing adjacent to the longitudinal slot, the inner wall of the outer housing is spaced from the outer wall of the inner housing by some distance adjacently to its longitudinal slot. Consequently, the outer housing and the inner housing do not abut against each other at that location, but a gap is present between the two housings, so that a larger part of the inner housing is available to enable a spring movement.
Furthermore the inner housing may have a substantially cylindrical inner wall, seen in sectional view, comprising two opposing recesses for guiding the pull beam, which recesses are disposed at equal angular distances from the longitudinal slot. The substantially cylindrical inner wall functions to guide the side edges of the gauze screen (and usually, as already noted before, the guide cams formed thereon). Accommodated in said recesses is a correspondingly shaped end of the pull beam. In this manner the pull beam can be prevented from being pulled out of the guides already before the side edges of the gauze screen have become detached therefrom.
As already noted before, the outer housing is fixed to the frame in question when the roller screen is being mounted. In this connection it may be advantageous for the outer housing to comprise a projecting mounting leg. Said mounting leg can be fixed to the frame by suitable fastening means (for example screws).
In a preferred embodiment the mounting leg extends substantially in radial direction with respect to the outer housing in that case. Such a position of the mounting leg provides a very universal mounting possibility.
Furthermore it may be advantageous to use an auxiliary section between the mounting leg and the frame, in particular when a sill projects beyond the front side of the frame and the guide is to be mounted on the sill.
The inner housing may consist of plastic material. The outer housing may be made of a metal such as aluminium, for example.
Finally it is preferable to use securing means for fixing the relative positions of the outer housing and the inner housing. Such securing means may be screw taps which are capable of engaging the outer side of the inner housing.
The invention furthermore relates to a guide intended for use in a roller screen according to the invention. Such a guide may already be used when the roller screen is first mounted , but it is also conceivable to exchange the original guide of an existing roller screen for the guide according to the invention.